@mixin flex ($jc: center, $ai: center) {
    display: flex;
    justify-content: $jc;
    align-items: $ai;
}
@mixin flex1 {
    display: flex;
}
@mixin jcontent($jc: flex-start) {
    justify-content: $jc;
}
@mixin aitems($ai: center) {
    align-items: $ai;
}
@mixin direction($dir: row) {
    flex-direction: $dir;
}
